The present invention relates to a component recognizing method and apparatus for executing positional detection or quality check (good or no good) of connection portions such as leads and electrodes existing on the mounting surface of electronic components to be mounted during component mounting for automatically mounting the electronic component on a printed board or a liquid crystal or plasma display panel board. The present invention additionally relates to an electronic component mounting method for mounting the electronic component on a board on the basis of positional information of the connection portions such as the leads and electrodes existing on the mounting surface of the electronic component detected by the above component recognizing method. The present invention further relates to an electronic component mounting apparatus for mounting the electronic component on the board on the basis of the positional information of the connection portions such as the leads and electrodes existing on the mounting surface of the electronic component detected by the above component recognizing apparatus.
Conventionally, with regard to the component recognizing method of this type, there have been known various structures. For example, there has been considered one that applies a visible light to an electronic component, receives light reflected from the object by means of a CCD camera and executes the positional detection of the connection portions such as the leads and electrodes existing on the mounting surface of the electronic component.
However, the above-mentioned structure has had the following issue. If a projection or the like exists near the leads and electrodes existing on the mounting surface of the electronic component and the visible light is reflected off the projection, then the light reflected off the projection or the like enters the CCD camera in addition to the light reflected on the leads, electrodes and the like. The projection or the like becomes noise for the connection portions, such as the leads and electrodes, to be recognized, for which the projection might be erroneously recognized as a lead or an electrode.
Accordingly, it is an object of the present invention to solve the above-mentioned issue and provide a component recognizing method and apparatus capable of correctly obtaining the positional information of the connection portions of an electronic component without recognizing a projection or the like located near the connection portions such as leads and electrodes existing on the mounting surface of the electronic component as well as an electronic component mounting method and apparatus capable of correctly mounting the electronic component on the basis of positional information of the connection portions obtained correctly.
FIG. 41 is a schematic perspective view of a prior art electronic component mounting apparatus.
In FIG. 41 are shown a main body 1 of an electronic component mounting apparatus, electronic components (occasionally abbreviated to xe2x80x9ccomponentsxe2x80x9d hereinafter) 2 to be mounted by the present mounting apparatus, a tray 4a on which the components 2 are placed, a tray supply section 4 that serves as a component supply section for automatically supplying the components 2 placed on the tray 4a, a head section 7 (nozzle 7a) for sucking one of the electronic components 2 in a mounting stage, a robot on the X-axis side (abbreviated to an X-axis robot hereinafter) that moves the head section 7 in the X-axis direction and constitutes part of an X-Y robot, robots 6a and 6b on the Y-axis side (abbreviated to Y-axis robots hereinafter) that move the head section 7 in the Y-axis direction and constitute part of the X-Y robot with the X-axis robot 5, a CCD camera 3A, and a height sensor 8A. The reference numeral 9 denotes a printed board to be mounted with the components 2.
FIG. 25 shows an example of the electronic component 2 to be mounted by the above-mentioned electronic component mounting apparatus. This electronic component 2 has a plurality of leads 2a on the left-hand and right-hand sides of a component body 2b, and the lead tips 2c of the leads 2a are mounted on the board 9.
In the prior art electronic component mounting apparatus, the CCD camera 3A is used for two-dimensional positional detection of the electronic component 2 that is the object, and the height sensor 8A is used for inspecting the floating of the leads of the electronic component 2.
As shown in FIG. 42, this height sensor 8A is to measure the height of the object at one specified point. The height sensor 8A shown in FIG. 42 is provided with a laser light source 8a, a focusing lens 8c for focusing the reflected light (scattered light) of the laser beam that has been emitted from this laser light source 8a and impinges on the electronic component 2 that is the object and a semiconductor position sensitive detector (abbreviated to PSD hereinafter) 8d that serves as a position detecting device on which the reflected light of the laser beam impinging on the lead tip 2c of the electronic component 2 is focused through the focusing lens 8c. The PSD 8d generates an electric signal correlated with the position of the focused light.
The prior art component recognizing method will be described next on the basis of the flowchart shown in FIG. 43 sequentially from Step S71 to Step S79.
Step S71: The electronic component 2 is sucked by the nozzle 7a. 
Step S72: The luminance image of the electronic component 2 is captured in the position of the CCD camera 3A.
Step S73: The position of the electronic component 2 is detected by processing this luminance image.
Step S74: The program flow jumps to Step S78 when no inspection is executed on the floating of the leads 2a of the electronic component 2.
Step S75: The electronic component 2 is moved so that the tips 2c of the leads 2a of the electronic component 2 each consistently come into the measurement position of the height sensor 8A, and then, height data of the lead tips 2c are measured. In the case of the electronic component 2 shown in FIG. 25, the two lines P1 and P2 shown in FIG. 25 are the height measurement lines of the lead tips 2c, and these measurement lines P1 and P2 are determined by the positional detection executed by the CCD camera 3A. First, the height measurement of the lead tips 2c of one side is executed along the first line P1 by moving the nozzle 7a in the X-axis direction, and after rotating the nozzle 7a by 180xc2x0, the height measurement of the lead tips 2c of the other side is executed along the second line P2 by moving the nozzle 7a in the X-axis direction. In the case where the electronic component 2 is a QFP component, the heights of the lead tips 2c of the four sides are taken in by segmentally executing a linear movement four times. In this case, the electronic component 2 are rotated by 90 degrees three times around the nozzle 7a for suction use.
Step S76: Positions of three lead tips 2c that are brought into contact with a theoretical imaginary surface when the electronic component 2 is mounted on the theoretical imaginary surface are calculated from three-dimensional positions (X, Y, Z) of all the lead tips 2c, and the imaginary surface is expressed by an expression. Then, distances of the three-dimensional positions (X, Y, Z) of all the lead tips 2c from the imaginary surface, i.e., the lead floating amounts are calculated.
Step S77: It is decided whether each of these lead floating amounts is exceeding a predetermined reference value. When the lead floating amount is exceeding the predetermined reference value, the program flow proceeds to Step S79. When all of the lead floating amounts are not exceeding the predetermined reference value, the program flow proceeds to Step S78.
Step S78: In the case of an electronic component that is not required to be inspected for the lead floating amount or determined as the normal component through the lead floating amount inspection, the electronic component is mounted in the specified position on the board 9, and then, the processing ends.
Step S79: An electronic component 2, the lead floating amount of which is exceeding the predetermined reference value, is disposed of as an abnormal component, and then the processing ends.
However, the above-mentioned prior art method has had the issue that the lead floating inspection cannot be executed by the height sensor 8A until the luminance image input is executed by the CCD camera 3A for the positional detection of the electronic component 2 and the measurement lines P1 and P2 are determined, every time the lead floating inspection is executed, resulting in much time required for the mounting of the electronic component 2.
Furthermore, the conventional height sensor 8A is to measure the height of the electronic component 2 on the specified line, and this has lead to the issue that the range of inspection is very small, lacking reliability.
Additionally, conventionally, in order to inspect the dropout or the like of a plurality of hemispherical bump (hemispherically projected) electrodes 120a arranged in a matrix form at the bottom portion of an electronic component 120 to be mounted on a printed board as shown in FIG. 40, there has been used, for example, an inspection method by means of a CCD camera.
This prior art inspection method, as shown in FIG. 44, has required to horizontally throw a flood of illumination to the hemispherical bump electrodes 120a of the electronic component 120 by means of a CCD camera 100. The reason is as follows. Even though there is a dropout hemispherical bump electrode 120a, then it is highly possible that the electrode or solder constituting part of the hemispherical bump electrode may exist underneath the dropout hemispherical bump electrode 120a. Therefore, if light is applied perpendicular to the hemispherical bump electrodes 120a from the front surface side of the CCD camera 100, then the electrode or solder reflects light even when there is a dropout hemispherical bump electrode 120a, leading to a difficulty in checking whether there is a dropout hemispherical bump electrode 120a. 
As shown in FIG. 45A, by applying light in the horizontal detection to the projecting bump electrode 120a, the actually existing hemispherical bump electrode 120a can be recognized as shown in FIG. 45B. FIG. 46A and FIG. 46B show an example in which light is applied to the hemispherical bump electrode 120a, while FIG. 47A and FIG. 47B show an example in which light is applied to a roughly hemispherical bump electrode 120a having a roughly flat portion in its bottom portion.
However, according to this illumination method, no light reflection can be theoretically obtained from the lowermost portion of the hemispherical bump electrode 120a, and this leads to a difficulty in recognizing the lowermost portion of the hemispherical bump electrode 120a, that is, the most important portion to be connected by solder to the printed board. Depending on the state of discoloration due to the oxidation of the surface of the hemispherical bump electrode 120a or depending on the state of dent in the surface of the hemispherical bump electrode 120a, the quantity of light reflected on the hemispherical bump electrode 120a varies. Therefore, the shape of the hemispherical bump electrode 120a has been allowed to be recognized only qualitatively. That is, it has been only allowed to make a relative evaluation by expressing the state of luster of individual hemispherical bump electrode 120a by an evaluation value such as the sum total of luminance values belonging to the hemispherical bump electrode 120a, examining the distribution of the evaluation value of the hemispherical bump electrode 120a, and making a decision on the occurrence of dropout of the hemispherical bump electrode 120a. For this reason, the conventional method has been used for checking the presence or absence of the hemispherical bump electrodes 120a at the bottom portion of the electronic component 120.
There has been a further issue that in the case where the height of the hemispherical bump electrode 120a is low, the portion that reflects light becomes small even though light is applied in the horizontal direction. Consequently, no sufficient quantity of light for the detection of the hemispherical bump electrode 120a can be obtained, and this has reduced the reliability in checking whether the hemispherical bump electrode 120a is present or absent.
In recent years, there has been generalized a component package of BGA (Ball Grid Array) as shown in FIG. 40 due to the large-scale integration of ICs. In the case of the BGA component, whose connection surface on a printed board becomes invisible once the component is mounted on the printed board, the inspection of the hemispherical bump electrodes 120a immediately before the mounting has a great importance. Under the present circumstances in which the IC packages are compacted and the importance of the function of inspecting the hemispherical bump electrodes 120a is increased, the importance of xe2x80x9cquantitatively detecting the amount of solder of the individual hemispherical bump electrode 120axe2x80x9d or xe2x80x9cquantitatively evaluating the shape of the individual hemispherical bump electrode 120axe2x80x9d is increased. However, neither of the aforementioned prior art methods has been able to make only the qualitative evaluation.
The present invention is made in view of the aforementioned conventional circumstances.
It is an object of the present invention to solve the aforementioned issues and provide a component recognizing method and component mounting method capable of rationally selecting and executing two-dimensional or three-dimensional positional detection of an electronic component at high speed and with high reliability.
Also, the present invention has the object of providing a component recognizing method and component inspecting method capable of totally measuring a plurality of bump electrodes arranged on a bottom portion of an electronic component, correctly detecting the volume or shape of each individual bump electrode, quantitatively evaluating the amount or shape of solder constituting the bump electrode, executing inspection of the bump electrodes, or the connection portions immediately before mounting the electronic component on a printed board, and improving the reliability of electronic component assembling.
In accomplishing these and other aspects, according to a first aspect of the present invention, there is provided a component recognizing method for applying light to connection portions that are leads or electrodes and exist on a mounting surface of an electronic component and executing positional detection of the connection portions by a height detecting section on the basis of a reflection light from the connection portions. The method according to the first aspect of the present invention comprises limiting a height measurement region of the height detecting section so that a noise object that exists behind or near the connection portion and reflects the light is excluded from the height measurement region of the reflection light to be detected by the height detecting section, and thereby removing the noise object.
According to a second aspect of the present invention, there is provided a component recognizing method according to the first aspect, wherein the height detecting section detects the positions of the connection portions by means of a semiconductor position sensitive device that serves as a height detection sensor.
According to a third aspect of the present invention, there is provided a component recognizing method according to the first or second aspect, wherein the noise removal is executed by presetting the height measurement region capable of detecting height positions of the connection portions about a height measurement reference plane within a height measurable region and executing height detection of the connection portions only within the height measurement region.
According to a fourth aspect of the present invention, there is provided a component recognizing method according to any one of the first through third aspects, wherein the noise removal is executed by presetting the height measurement region capable of detecting height positions of the connection portions about a height measurement reference plane within a height measurable region as a height translation table, handling height data that belongs to height data of the connection portion and is located outside the height measurement region as invalid height data according to the height translation table, handling height data located within the height measurement region as valid height data according to the height translation table, and executing height detection of the connection portions on the basis of the valid height data.
According to a fifth aspect of the present invention, there is provided a component recognizing method according to any one of the first through fourth aspects, and further comprising determining a processing area according to a size of the electronic component on the basis of an image of the electronic component detected only within the height measurement region, roughly detecting a center and an inclination of the electronic component by sampling inside a window of the determined processing area in the image of the electronic component to obtain a rough position of the electronic component, detecting positions of all of the connection portions in the image of the electronic component on the basis of the size of the component and the rough position of the electronic component, and detecting a correct position of the electronic component in the image of the electronic component from the positions of all the connection portions.
According to a sixth aspect of the present invention, there is provided an electronic component mounting method for mounting the electronic component on a is board on the basis of positional information of the connection portions of the electronic component detected by the component recognizing method according to any one of the first through fifth aspects.
According to a seventh aspect of the present invention, there is provided an electronic component mounting method according to the sixth aspect, further comprising holding the electronic component by a component holding member of a head section, deciding whether adjustment of the height measurement region is required and then, adjusting the height measurement region when the adjustment of the height measurement region is needed, adjusting a height of the component holding member on the basis of the height measurement region, capturing the height data of the component, detecting the position of the electronic component by the height detecting section, and mounting the electronic component in a specified position of the board by means of the component holding member by driving the head section on the basis of the height position information recognized by the height detecting section.
According to an eighth aspect of the present invention, there is provided a component recognizing apparatus comprising an illumination unit for applying light to a connection portions that are leads or electrodes and exist on a mounting surface of an electronic component, a height detecting section for executing positional detection of the connection portions on the basis of light that is applied from the illumination unit and reflected on the connection portions, and a noise removing section (304) for limiting a measurement region of the height detecting section so that a noise object that exists behind or near the connection portion and reflects the light is excluded from the measurement region of the reflection light detected by the height detecting section, thereby removing the noise object.
According to a ninth aspect of the present invention, there is provided a component recognizing apparatus according to the eighth aspect, wherein the height detecting section detects the positions of the connection portions by means of a semiconductor position sensitive device that serves as a height detection sensor.
According to a tenth aspect of the present invention, there is provided a component recognizing apparatus according to the eighth or ninth aspect, wherein the noise removing section presets a height measurement region capable of detecting a height positions of the connection portions about a height measurement reference plane within a height measurable region and executes height detection of the connection portions only within the height measurement region.
According to an eleventh aspect of the present invention, there is provided a component recognizing apparatus according to any one of the eighth through tenth aspects, wherein the noise removing section presets the height measurement region capable of detecting the height positions of the connection portions about the height measurement reference plane within the height measurable region as a height translation table, handles height data that belongs to the height data of the connection portion and is located outside the height measurement region as invalid height data according to the height translation table, handles the height data located within the height measurement region as valid height data according to the height translation table, and executes height detection of the connection portions on the basis of the valid height data.
According to a twelfth aspect of the present invention, there is provided a component recognizing apparatus according to any one of the eighth through eleventh aspects, further comprising a processing area determining means for determining a processing area on the basis of a size of the electronic component in an image of the electronic component detected only within the height measurement region, a center and inclination detecting means for roughly detecting a center and an inclination of the electronic component by sampling inside a window of the determined processing area in the image of the electronic component to obtain a rough portion of the electronic component, a connection portion position detecting means for detecting the positions of all of the connection portions in the image of the electronic component on the basis of the size of the component and the rough position of the electronic component, and a connection portion center and inclination detecting means for detecting the correct position of the electronic component in the image of the electronic component from the positions of all the connection portions.
According to a thirteenth aspect of the present invention, there is provided an electronic component mounting apparatus for mounting the electronic component on a board on the basis of positional information of the connection portions of the electronic component detected by the component recognizing apparatus according to any one of the eighth through twelfth aspects.
According to a fourteenth aspect of the present invention, there is provided an electronic component mounting apparatus according to the thirteenth aspect, further comprising a head section for holding the electronic component by a component holding member and adjusting a height of the component holding member on the basis of the height measurement region, and a control section for mounting the electronic component in a specified position of the board by means of the component holding member by driving the head section on the basis of the height position information recognized by the height detecting section.
According to a fifteenth aspect of the present invention, there is provided a component recognizing method employing a luminance image capturing means for obtaining is luminance image data of a surface of an electronic component viewed from a specified direction and a height image capturing means for obtaining height image data of a surface of the electronic component viewed from a specified direction, for executing positional detection of the electronic component by independently selectively using two-dimensional positional detection by the luminance image capturing means and three-dimensional positional detection by the height image capturing means.
According to a sixteenth aspect of the present invention, there is provided a component recognizing method according to the fifteenth aspect, wherein the luminance image capturing means and the height image capturing means are independently selectively used according to a shape feature of the electronic component.
According to a seventeenth aspect of the present invention, there is provided a component recognizing method according to the fifteenth aspect, wherein the luminance image capturing means and the height image capturing means are independently selectively used according to an inspection item to be executed on the electronic component.
According to an eighteenth aspect of the present invention, there is provided a component recognizing method according to any one of the fifteenth through seventeenth aspects, wherein the luminance image data obtained from the luminance image capturing means and the height image data obtained from the height image capturing means are processed by an identical image processing means by setting a height coordinate system of the height image data so that a direction directed from the electronic component toward the height image capturing means becomes positive.
According to a nineteenth aspect of the present invention, there is provided a component recognizing method according to any one of the fifteenth through eighteenth aspects, wherein the electronic component is constructed so that a plurality of leads are projecting from sides of a body of the component and tips of the leads are to be mounted on a board.
According to a twentieth aspect of the present invention, there is provided a component mounting method for transporting an electronic component from a component supply section onto a board and mounting the electronic component on the board. The method according to the twentieth aspect of the present invention comprises selecting either one of a luminance image capturing means for obtaining luminance image data of a surface of the electronic component viewed from a specified direction and a height image capturing means for obtaining height image data of a surface of the electronic component viewed from a specified direction in a transport path of the electronic component, executing positional detection of the electronic component by the selected one of the luminance image capturing means and the height image capturing means in transporting the electronic component from the component supply section onto the board, and mounting the electronic component on the board on the basis of information obtained through the positional detection.
According to a twenty first aspect of the present invention, there is provided a component mounting method according to the twentieth aspect, wherein the positional detection of the electronic component is executed by selecting either the luminance image capturing means or the height image capturing means according to a shape feature of the electronic component.
According to a twenty second aspect of the present invention, there is provided a component mounting according to the twentieth aspect, wherein the positional detection of the electronic component is executed by selecting either the luminance image capturing means or the height image capturing means according to an inspection item to be executed on the electronic component.
According to a twenty third aspect of the present invention, there is provided a component recognizing method comprising capturing a height image of a bottom portion of an electronic component having a plurality of bump electrodes in a bottom portion of the component as two-dimensional height image data by means of a height detection sensor while obtaining the height image data of the bump electrodes on surfaces parallel to a reference surface (for example, a bottom surface of the component) and imaginarily located in a direction perpendicular to the reference surface, extracting individual bump electrodes from the height image data, and detecting volumes of the extracted individual bump electrodes.
According to a twenty fourth aspect of the present invention, there is provided a component recognizing method according to the twenty third aspect, wherein the detection of the volumes of the bump electrodes of the electronic component is executed within an interval from when the electronic component is sucked from a component supply section by a nozzle of an electronic component mounting apparatus to when the electronic component is mounted on a board.
According to a twenty fifth aspect of the present invention, there is provided a component recognizing method according to the twenty third or twenty fourth aspect, wherein the height detection sensor captures the two-dimensional height image data by moving the electronic component in a direction perpendicular to a scanning direction of a laser beam or moving the height detection sensor in the direction perpendicular to the scanning direction of the laser beam while linearly scanning the laser beam on a straight line.
According to a twenty sixth aspect of the present invention, there is provided a component inspecting method for evaluating the electronic component as abnormal when the volume of any bump electrode detected by the component recognizing method according to any one of the twenty third through twenty fifth aspects does not fall within a predetermined range of reference.
According to a twenty seventh aspect of the present invention, there is provided a component mounting method for mounting on a board an electronic component that is not evaluated as abnormal by the component inspecting method according to the twenty sixth aspect.
According to a twenty eighth aspect of the present invention, there is provided a component recognizing method comprising capturing a height image of a bottom portion of an electronic component having a plurality of bump electrodes in a bottom portion of the component as two-dimensional height image data by means of a height detection sensor while obtaining the height image data of the bump electrodes on surfaces parallel to a reference surface and imaginarily located in a direction perpendicular to the reference surface, extracting individual bump electrodes from the height image data, and detecting shapes of the extracted individual bump electrodes.
According to a twenty ninth aspect of the present invention, there is provided a component recognizing method according to the twenty eighth aspect, wherein the detection of the shapes of the bump electrodes of the electronic component is executed within an interval from when the electronic component is sucked from a component supply section by a nozzle of an electronic component mounting apparatus from a component supply section to when the electronic component is mounted on a board.
According to a thirtieth aspect of the present invention, there is provided a component recognizing method according to the twenty eighth or twenty ninth aspect, wherein the height detection sensor captures the two-dimensional height image data by moving the electronic component in a direction perpendicular to a scanning direction of a laser beam or moving the height detection sensor in the direction perpendicular to the scanning direction of the laser beam while linearly scanning the laser beam on a straight line.
According to a thirty first aspect of the present invention, there is provided a component inspecting method for evaluating the electronic component as abnormal when the shape of any bump electrode detected by the component recognizing method according to any one of the twenty eighth through thirtieth aspects falls outside a predetermined shape of reference.
According to a thirty second aspect of the present invention, there is provided a component mounting method for mounting on a board an electronic component that is not evaluated as abnormal by the component inspecting method according to the thirty first aspect.
According to a thirty third aspect of the present invention, there is provided a component recognizing method for applying light to connection portions that are leads or electrodes and exist on a mounting surface of an electronic component and executing positional detection of the connection portions by a height detecting section on the basis of a reflection light from the connection portions. The method according to the thirty third aspect of the present invention comprises limiting a height measurement region of the height detecting section so that a noise object that exists behind or near the connection portion and reflects the light is excluded from the height measurement region of the reflection light to be detected by the height detecting section, and thereby removing the noise object, wherein in executing the positional detection, the positional detection of the electronic component is executed independently selectively using two-dimensional positional detection by a luminance image capturing means and three-dimensional positional detection by a height image capturing means, the luminance image capturing means obtaining luminance image data of a surface of an electronic component viewed from a specified direction and the height image capturing means obtaining height image data of a surface of the electronic component viewed from a specified direction, and a height image of a bottom portion of the electronic component having a plurality of bump electrodes in a bottom portion of the component is captured as two-dimensional height image data by means of a height detection sensor, individual bump electrodes are extracted from the height image data, and volumes or shapes of the extracted individual bump electrodes are detected.